“Spending time in nature provides protections against a startling range of diseases, including depression, diabetes, obesity, ADHD, cardiovascular disease, cancer, and many more, research shows. How this exposure to green space leads to better health has remained a mystery. After reviewing hundreds of studies examining nature’s effects on health, an environment and behavior researcher believes the answer lies in nature’s ability to enhance the functioning of the body’s immune system. One way to understand the relationship between nature, health, and the immune system is that exposure to nature switches the body into “rest and digest” mode, which is the opposite of the “fight or flight” mode.”